1. Field of the Invention
The present invention relates to a thermoelectric conversion material and its manufacturing method, and a thermoelectric conversion device using the same.
2. Description of the Related Art
A thermoelectric conversion device is used to thermoelectric power generation, thermoelectric cooling and so on. For example, thermoelectric power generation is a type of power generation that converts thermal energy into electric energy using a thermoelectromotive force caused by temperature difference in a thermoelectric conversion device.
The energy conversion efficiency of the thermoelectric conversion device is determined depending on Seebeck coefficient, electrical conductivity and thermal conductivity of a thermoelectric conversion material. More specifically, the energy conversion efficiency of the thermoelectric conversion material is in proportion to the square of Seebeck coefficient and the electrical conductivity, and in inverse proportion to the thermal conductivity. Therefore, it is required that the development of a thermoelectric conversion material having high Seebeck coefficient or high electrical conductivity or low thermal conductivity so as to improve the energy conversion efficiency of a thermoelectric conversion device.